1. Field of the Invention
The present invention relates to a method and apparatus for establishing a Peer-to-Peer (P2P) connection in a wireless communication system. More particularly, the present invention relates to a method and apparatus for adaptive P2P communication selection in consideration of a wireless environment between Mobile Stations (MSs).
2. Description of the Related Art
In a wireless communication system, whenever first and second Mobile Stations (MSs) desire to communicate with each other, the first or transmitting MS must make a call to the second or receiving MS through a wireless communication network regardless of the distance between the transmitting and receiving MSs. That is, a connection with the receiving MS is established via a Base Station (BS), a mobile switching center, or the like, constituting the wireless communication system, regardless of the distance between the transmitting MS and the receiving MS. However, if the distance between the transmitting MS and the receiving MS is very close, direct communication can be more reasonable. Direct communication, that is, communication that is not established via the BS, is referred to as Peer-to-Peer (P2P) communication. Various services can be provided through the P2P communication, such as, transmission of a massive file, Voice over Internet Protocol (VoIP), video conference, etc. Also, the P2P communication can provide the same service quality as that conventionally provided via the BS.
The MSs conventionally use a different frequency band for general P2P communication than a frequency band allocated to the wireless communication system. To process the additional frequency band, a separate Radio Frequency (RF) transmitting/receiving apparatus is used. For example, Infrared Data Association (IrDA) communication, Bluetooth communication, etc., are used in the P2P communication. Alternatively, when the P2P communication and the wireless communication use the same frequency band, bandwidth efficiency can be improved by flexibly adjusting each transmission band through effective resource management so long as interference is prevented. One project that is researching such P2P communication is the Wireless world Initiative NEw Radio (WINNER) system in Europe.
FIG. 1 illustrates an example of a P2P communication environment in a wireless communication system.
Referring to FIG. 1, a plurality of MSs 102, 104 and 106 are located in a service coverage area of a BS 100, and the MS_y 108 is located in a service coverage area of another BS 110. The MSs 102 to 108 can communicate with receiving MSs via the corresponding BSs 100 and 110. Although an additional P2P communication module is not included, wireless resources of the mobile communication system can be reused to perform P2P communication between the MSs.
In the wireless communication system of FIG. 1, when the MS_1 102 desires to communicate with the MS_2 104, the MS_1 102 determines whether the connection will be established in a P2P communication mode or a wireless communication mode. For example, when the MS_1 102 detects that the receiving MS (i.e., the MS_2 104) is located close to the MS_1 102, the MS_1 102 can request the BS 100 to establish a P2P connection with the MS_2 104. Alternatively, the MS_1 102 may attempt direct P2P communication with the MS_2 104 not via the BS 100. In addition, although the MS_1 102 does not detect the location of the receiving MS (i.e., the MS_2 104), the MS_1 102 can perform P2P communication by gathering information of the MS_2 104. However, if the MS_1 102 is located in the service coverage area of the BS 100 and desires P2P communication with the MS_y 108 whose location is not detected, the MS_1 102 cannot perform P2P communication with the MS_y 108 because the MS_1 102 cannot gather information of the MS_y 108 due to a distance between the MS_1 102 and the MS_y 108. In such a case, in order to communicate with the MS_y 108 (or the MS_x 106), it is preferable that the MS_1 102 establishes a BS-assisted connection instead of establishing the P2P connection.
To perform communication, the MS_1 102 must select either the P2P communication mode or the wireless communication mode by considering a wireless environment and a distance from the receiving MS, which is difficult in practice. Even if the selection of a communication mode is achieved by the MS_1 102 in consideration of the wireless environment and the distance from the receiving MS, there is no guarantee that the selected communication mode is effective in terms of resource utilization.
As described above, when an MS attempts a call connection with another MS in a wireless communication system, there is no method of adaptively selecting a communication mode between BS-assisted communication (i.e., wireless communication) and P2P communication among MSs by considering effective utilization of overall resources from the viewpoint of a BS.